Screw driver attachment

ABSTRACT

A device for attachment to a power tool having a rotary output, such as a drill, which device includes a housing having an input member adapted to be connected to said tool output. The device has an output member with a screwdriver bit attached thereto. This output member is normally disengaged from the input member but is connected thereto and driven thereby when the bit is pressed against a work member.

United States Patent [72] Inventors Appl. No. Filed Patented AssigneeCharles R. Turner, III

Littletown, Pa.; Raymond G. Bowers, Randallstown, Md.; Clyde R. Smith,New Freedom, Pa.; Paul C. Behrman, Jr., Kingsviile, Md.; James A.Cummings, Baltimore, Md.

Sept. 30, 1969 Aug. 17, 197 l I The Black and Decker ManufacturingCompany Towson, Md.

SCREW DRIVER ATTACHMENT 5 Claims, 3 Drawing Figs.

U.S. CL. 192/56 R, 81152.4, 144/32, 192/67, 279/1 A Int. Cl ..Fl6d43/20, F1-6d 1 H04 Field oi Search 192/56, 67;

81/524; 64/29, 30; 144/32; 279/l R, l A, l B

[56] References Cited UNITED STATES PATENTS 2,225,091 12/1940 Wilhide192/67 X 2,603,325 7/1952 Pickard l92/67 1,711,520 5/1929 Decker..144/32 X 2,068,745 1/1937 Hall 8l/52.4 X 2,161,300 6/1939 Kolstad.81/52.4 X 3,056,441 10/1962 Helms 144/32 X 3,484,114 12/1969 Rodin144/32 X Primary Examiner-Allan D. Herrmann Attorneys-Leonard Bloom,Joseph R. Slotnik and Edward D.

Murphy ABSTRACT: A device for attachment to a power tool having a rotaryoutput, such as a drill, which device includes a housing having an inputmember adapted to be connected to said tool output. The device has anoutput member with a screwdriver bit attached thereto. This outputmember is normally disengaged from the input member but is connectedthereto and driven thereby when the bit is pressed against a workmember.

PATENTED nus] 115m lNVENTORS CHARLES B. TURNER Ill RAYMOND G. BOWERSCLYDE R. SMITH PAUL C. BEHRMAN JR.

JAME ACUMMINGS BY w J -v ATTORNEY SCREW DRIVER ATTACHMENT SUMMARY OF THEINVENTION The present invention is directed to a unitary attachmentwhich converts a powered mechanism having a straight rotary output toone whose output rotates only when pressed against a work member andwhich ceases to rotate when resistance torque thereon exceeds apredetermined level. The attachment is useful, particularly inconverting the conventional drill to a screwdriver, embodies simplicity,reliability and durability, is compact and light in weight, and isrelatively inexpensive to make.

Main objects of the present invention, therefore, are to provide animproved attachment for converting a powered mechanism having a straightrotary output, such as a drill, to one whose output includes ascrewdriving bit and which rotates only when the bit is pressed axiallyagainst a work member and which slips (or ceases to rotate) when thetorque resistance level (offered by the work member) exceeds apredetermined level.

Further important objects of the present invention are to provide animproved attachment of the above character which embodies utility,simplicity and durability, is relatively small, compact and lightweight,and is relatively inexpensive to manufacture and reliable in use.

Other objects and advantages of the present invention will become moreapparent from a consideration of the detailed description to followtaken together with the drawings annexed hereto.

BROAD STATEMENT OF THE INVENTION Broadly described, the presentinvention relates to a unitary attachment comprising input and outputmembers telescopically engaged for slideable guiding support, a housingslideably and rotatably embracing said input and output members andretaining said members in telescopic engagement, said input memberhaving a portion extending outwardly of said housing for removableattachment to said rotary output, cooperable clutch means formed on saidinput and output members and adapted to transmit rotation from saidinput member to said output member, means normally maintaining saidclutch means disengaged but allowing cooperable engagement therebetweenwhen axial force is applied to said output member, said clutch meansbeing adapted to slip upon application of a predetermined level oftorque resistance to said output member.

In another aspect, the present invention relates to a unitary attachmentfor a portable, powered'device having a rotary output, said attachmentcomprising a housing, an input member slideably and rotatably disposedwithin said housing and having a portion extending outwardly thereofadapted to be secured to said rotary output, said attachment having anoutput member slideably and rotatably supported by said housing andhaving a portion closely slideably received in a bore in said inputmember, cooperable clutch means including a transverse pin fixed to saidoutput member and receivable in cooperable grooves forged in said inputmember to transmit rotation from said input member to said outputmember, compression spring means in said bore and engaging said inputand output members to normally maintain said clutch means disengaged butallowing cooperable engagement therebetween when axial force is appliedto said output member, said clutch means being adapted to slip uponapplication of a predetermined level of torque resistance to said outputmember.

In still another aspect. the present invention relates to a unitaryattachment for a portable, powered device having a rotary output, saidattachment comprising a housing, an input member slideably and rotatablydisposed within said housing and having a portion extending outwardlythereof adapted to be secured to said rotary output, said attachmenthaving an outputmember slideably and rotatably supported by saidhousing, cooperable clutch means formed on said input and output membersand adapted to transmit rotation from said input member to said outputmember, means normally maintaining said clutch means disengaged butallowing cooperable engagement therebetween when axial force is appliedtosaid output member, said clutch means being adapted to slip uponapplication of a predetermined level of torque resistance to said outputmember, said housing including an in-turned flange defining a reducedopening through which said output member extends, said output memberbeing restrained against axial movement outwardly of said housing by atransverse pin forming one part of said clutch means, said pin beingdisposed within said housing and adjacent said in-turned flange.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view, partly in sectionand partly in elevation, illustrating an attachment embodying thepresent invention;

FIG. 2 is a sectional view of FIG. 1 taken along the line 2-2 thereof;and

FIG. 3 is a sectional view of FIG. 1 taken along the line 3-3 thereof.

DETAILED DESCRIPTION Referring now more specifically to the drawings, anattachment embodying the present invention is illustrated generally at11 in FIG. 1 and is seen to include an annular housing 13. An inputmember or driver 15 is slidably and rotatably disposed in the housing 13and is retained therein by a retaining ring 17. The driver 15 has areduced shaftlike end 19 extending rearwardly of the housing 13 adaptedto be connected to the rotary output of a portable, powered device. Forexample, the driver end 19 may be connected to a chuck 21 fixed to aspindle 23 of a portable drill 25 to impart rotary movement to thedriver 15 from the drill 25.

The housing 13 has an intumed flange 27 at its forward end which definesa reduced opening 29. A generally cylindrical output member 31 extendsthrough the opening 21 into the housing 13 and is slidably disposedwithin a bore 33 in the end of the driver 15. The output member 31 has acentral bore 35 adapted to receive a screwdriver bit 37. The member 31and the bit 37 are suitably keyed together for conjoint rotation, forexample, the bore 35 and the bit 37 may have complementary hexagonal orotherwise noncircular cross-sectional configurations. If desired, detentball means 38 may be provided in the output member 31 to releasablyretain the screwdriver bit 37 in place therein. A split ring 53 on themember 31 holds the detent ball 38 in place.

The driver 15 and output member 31 are provided with engageable clutchmeans adapted to transmit rotation from said driver 15 to said outputmember 31. Thus, the driver 15 is provided with diametrically disposedsets of grooves 39, 41 and 43, 45 formed therein by forging and adaptedto cooperatively receive a cylindrical pin 47 which extends transverselythrough and rotates with the output member 31. The clutch partsincluding the pin 47 and the sets of grooves 39, 41 and 43, 45 arenormally separated by means of a compression spring 49 having one endseated in a pocket 51 in the bottom of the bore 33 and its other endreceived in the bore 35 in the output member 31 and bearing against thepin 47. The force of the spring 49 normally holds the driver 15 againstthe retaining ring 17 and the clutch pin 47 against the inturned flange27; however, the driver 15 and output member 31 are selectively movabletoward each other against the spring 49 to bring the pin 47 intocooperative clutching engagement with the grooves 39, 41 or the slots43, 45 whereby to transmit rotation from the driver 15 to the outputmember 31.

As shown in FIG. 1, the output member 31 is supported by the housing 13at the opening 29 and by the driver 15 at its bore 33. When the tool bit37 is pressed against a work member, the driver 15 and output member 31are caused to move relative to one another against the force of thespring 49 whereupon the pin 47 engages in the grooves 39, 41, or 43, 45

and causes the driver member 31 and the bit 37 to rotate with the driver15. This direct drive continues until either the tool bit 37 is releasedfrom the work member or when the torque resistance on the tool bit 37and the output member 31 reaches the slip level where the pin 47 camsout of its groove 39, 41 or 43, 45.

It will be appreciated that the attachment of the present invention maybe used with a variety of powered devices of which portable electricdrills are one example. This attachment embodies obvious simplicity, andits components, particularly the clutch parts, afford inexpensivemanufacturing techniques. Thus, the pin 47 may be a bearing roller andthe grooves 39, 41 and 43, 45 may be formed by a simple forging processas distinguished from the relatively expensive machining processesheretofore used in clutch components of this type.

While a preferred embodiment of the present invention has beenillustrated and described above in detail, various additions,substitutions, modifications and omissions may be made thereto withoutdeparting from the spirit of the invention.

We claim:

1. A unitary attachment for a portable, powered device having a rotaryoutput, said attachment comprising input and output memberstelescopically engaged for slideable guiding support, a housingslideably and rotatably embracing said input and output members andretaining said members in telescopic engagement, said input memberhaving a portion extending outwardly of said housing for removableattachment to said rotary output, cooperable clutch means formed on saidinput and output members and adapted to transmit rotation from saidinput member to said output member, means normally maintaining saidclutch means disengaged but allowing cooperable engagement therebetweenwhen axial force is applied to said output member, said clutch meansbeing adapted to slip upon application of a predetermined level oftorque resistance to said output member.

2. An attachment as defined in claim 1 wherein said input member has abore closely slidably receiving said output member.

3. An attachment as defined in claim 2 which includes compression springmeans within said bore and engaging said input and output members tonormally maintain said clutch means disengaged.

4. A unitary attachment for a portable, powered device having a rotaryoutput, said attachment comprising a housing, an input member slideablyand rotatably disposed within said housing and having a portionextending outwardly thereof adapted to be secured to said rotary output,said attachment having an output member slideably and rotatablysupported by said housing and having a portion closely slideablyreceived in a bore in said input member, cooperable clutch meansincluding a transverse pin fixed to said output member and receivable incooperable grooves forged in said input member to transmit rotation fromsaid input member to said output member, compression spring means insaid bore and engaging said input and output members to normallymaintain said clutch means disengaged but allowing cooperable engagementtherebetween when axial force is applied to said output member, saidclutch means being adapted to slip upon application of a predeterminedlevel of torque resistance to said output member.

5. A unitary attachment for a portable, powered device having a rotaryoutput, said attachment comprising a housing, an input member slideablyand rotatably disposed within said housing and having a portionextending outwardly thereof adapted to be secured to said rotary output,said attachment having an output member slideably and rotatablysupported by said housing, cooperable clutch means formed on said inputand output members and adapted to transmit rotation from said inputmember to said output member, means normally maintaining said clutchmeans disengaged but allowing cooperable engagement therebetween whenaxial force is applied to said out m member, said clutch means beingadapted to slip upon app lcation of a predetenmned level of torqueresistance to said output member, said housing including an inturnedflange defining a reduced opening through which said output memberextends, said output member being restrained against axial movementoutwardly of said housing by a transverse pin forming one part of saidclutch means, said pin being disposed within said housing and adjacentsaid inturned flange.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3s599,765 Dat d AUGUST 17, 1971 Inventor(s) ES R. TURNER, I ET AL It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

COLUMN 1, AFTER LINE 32, THE MATERIAL FROM COLUMN 2, LINES 15-22, SHOULDBE INSERTED.

COLUMN 1 AFTER LTNE 35, :NsERT ATTACHMENT FOR A PORTABLE,

POWERED DEVICE HAVING A ROTARY OUTPUT, SAID Signed and sealed this 30thday of May 1972.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. ROBERT GOTTSCHALK At testing Officer Commissionerof Patents FORM PC4059 USCOMM-DC GUSTO-P69 U.S GOVERNMENT PRlNTINGOF'lCEI ID. O-IGO-Sll

1. A unitary attachment for a portable, powered device having a rotaryoutput, said attachment comprising input and output memberstelescopically engaged for slideable guiding support, a housingslideably and rotatably embracing said input and output members andretaining said members in telescopic engagement, said input memberhaving a portion extending outwardly of said housing for removableattachment to said rotary output, cooperable clutch means formed on saidinput and output members and adapted to transmit rotation from saidinput member to said output member, means normally maintaining saidclutch means disengaged but allowing cooperable engagement therebetweenwhen axial force is applied to said output member, said clutch meansbeing adapted to slip upon application of a predetermined level oftorque resistance to said output member.
 2. An attachment as defined inclaim 1 wherein said input member has a bore closely slidably receivingsaid output member.
 3. An attachment as defined in claim 2 whichincludes compression spring means within said bore and engaging saidinput and output members to normally maintain said clutch meansdisengaged.
 4. A unitary attachment for a portable, powered devicehaving a rotary output, said attachment comprising a housing, an inputmember slideably and rotatably disposed within said housing and having aportion extending outwardly thereof adapted to be secured to said rotaryoutput, said attachment having an output member slideably and rotatablysupported by said housing and having a portion closely slideablyreceived in a bore in said input member, cooperable clutch meansincluding a transverse pin fixed to said output member and receivable incooperable grooves forged in said input member to transmit rotation fromSaid input member to said output member, compression spring means insaid bore and engaging said input and output members to normallymaintain said clutch means disengaged but allowing cooperable engagementtherebetween when axial force is applied to said output member, saidclutch means being adapted to slip upon application of a predeterminedlevel of torque resistance to said output member.
 5. A unitaryattachment for a portable, powered device having a rotary output, saidattachment comprising a housing, an input member slideably and rotatablydisposed within said housing and having a portion extending outwardlythereof adapted to be secured to said rotary output, said attachmenthaving an output member slideably and rotatably supported by saidhousing, cooperable clutch means formed on said input and output membersand adapted to transmit rotation from said input member to said outputmember, means normally maintaining said clutch means disengaged butallowing cooperable engagement therebetween when axial force is appliedto said output member, said clutch means being adapted to slip uponapplication of a predetermined level of torque resistance to said outputmember, said housing including an inturned flange defining a reducedopening through which said output member extends, said output memberbeing restrained against axial movement outwardly of said housing by atransverse pin forming one part of said clutch means, said pin beingdisposed within said housing and adjacent said inturned flange.